Interface Kit: Adjust max size and default alignment...

...on controls where it makes sense:
- BRadioButton and BCheckBox now return their preferred size as their
maximum.
- BRadioButton, BCheckBox and BTextControl now use left alignment by
default, as this is the most common use case for them.

src/kits/interface/TextControl.cpp

@@ -850,6 +850,17 @@ BTextControl::PreferredSize()
 }
 
 
+BAlignment
+BTextControl::LayoutAlignment()
+{
+	CALLED();
+
+	_ValidateLayoutData();
+	return BLayoutUtils::ComposeAlignment(ExplicitAlignment(),
+		BAlignment(B_ALIGN_LEFT, B_ALIGN_VERTICAL_UNSET));
+}
+
+
 BLayoutItem*
 BTextControl::CreateLabelLayoutItem()
 {